Indyrose,

Your soil is inappropriate for this plant, which wants to dry out between waterings.

Do a search here for 'jade plant' or 'Crassula ovata' and you'll find a wealth of information on how to cultivate it.

Basically, it seems from the pictures that you're drowning it. Depot it, clean the old soil away from the roots, let dry a few days, and in the meantime you'll have found a suitable soil (one that has great drainage) in which to repot it in.

Hi, Indyrose! Jeffrey is correct.
The algae/moss growing atop the soil is a prime indication that there's too much
moisture in the mix....for a Jade, that is. The moss seems quite happy! ;)

In addition to what Jeff has advised, I would suggest that you remove any affected leaves.
Removing the leaves will encourage new growth.

Josh

Thanks for the tips! They're in my greenhouse where *everything* get frequently watered and the warmth and humidity is loved by the moss.-- But I guess not by the Jade!

Indyrose